Coroutines Test 入門 / Android Test Night #8

Transcript

1. Android Test Night #8
   2023/03/10
   Coroutines Test 入門
   

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2. ● Kenji Abe
   ● @STAR_ZERO
   ● Google Developers Expert for Android, Kotlin
   ● DeNA Co., Ltd.
   

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3. // build.gradle
   dependencies {
   // ...
   testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.4")
   }
   

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4. supsend関数のテスト
   

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5. class Sample {
   suspend fun run(): String {
   return "hoge"
   }
   }
   

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6. class SampleTest {
   @Test
   fun testRun() = runTest {
   val sample = Sample()
   val result = sample.run()
   assert(result == "hoge")
   }
   }
   

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7. class SampleTest {
   @Test
   fun testRun() = runTest {
   val sample = Sample()
   val result = sample.run()
   assert(result == "hoge")
   }
   }
   

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8. ● runBlockingのようなもの
   ● delay関数はすべてスキップされる
   ○ Vertial Timeを制御することができる
   ● TestScopeが使用される
   runTest
   

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9. TestDispatchers
   

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10. ● StandardTestDispatcher
    ○ runTestデフォルト
    ○ TestCoroutineSchedulerを使用するシンプルなDispatcher
    ● UnconfinedTestDispatcher
    ○ Dispatchers.Unconfinedのようなもの
    ○ トップレベルのlaunch/asyncがすぐに実行される
    TestDispatchers
    

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11. class SampleTest {
    @Test
    fun testRun() = runTest {
    val sample = Sample()
    val result = sample.run()
    assert(result == "hoge")
    }
    }
    

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12. @Test
    fun test() = runTest {
    var result = 0
    launch {
    result = 1
    }
    assert(result == 1)
    }
    

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13. @Test
    fun test() = runTest {
    var result = 0
    launch {
    result = 1
    }
    assert(result == 1)
    }
    ❌ Failed
    

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14. @Test
    fun test() = runTest {
    var result = 0
    launch {
    result = 1
    }
    assert(result == 1)
    }
    ①
    ②
    ③
    

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15. @Test
    fun test() = runTest {
    var result = 0
    launch {
    result = 1
    }
    runCurrent()
    assert(result == 1)
    }
    ✅ Success
    

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16. @Test
    fun test() = runTest {
    var result = 0
    launch {
    result = 1
    }
    runCurrent()
    assert(result == 1)
    }
    ①
    ②
    ③
    ④
    

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17. @Test
    fun test() = runTest {
    var result = 0
    launch {
    delay(1000)
    result = 1
    }
    runCurrent()
    assert(result == 1)
    }
    

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18. @Test
    fun test() = runTest {
    var result = 0
    launch {
    delay(1000)
    result = 1
    }
    runCurrent()
    assert(result == 1)
    }
    ❌ Failed
    

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19. @Test
    fun test() = runTest {
    var result = 0
    launch {
    delay(1000)
    result = 1
    }
    runCurrent()
    assert(result == 1)
    }
    ①
    ②
    ③
    ④
    ⑤
    

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20. @Test
    fun test() = runTest {
    // ...
    advanceUntilIdle()
    // または
    advanceTimeBy(1001)
    assert(result == 1)
    }
    ✅ Success
    

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21. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    var result = 0
    launch {
    result = 1
    }
    assert(result == 1)
    }
    

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22. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    var result = 0
    launch {
    result = 1
    }
    assert(result == 1)
    }
    ✅ Success
    

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23. Mainスレッド対応
    

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24. class Sample {
    suspend fun run(): String =
    withContext(Dispatchers.Main) {
    "hoge"
    }
    }
    

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25. @Test
    fun testRun() = runTest {
    val sample = Sample()
    val result = sample.run()
    assert(result == "hoge")
    }
    

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26. @Test
    fun testRun() = runTest {
    val sample = Sample()
    val result = sample.run()
    assert(result == "hoge")
    }
    

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27. @Before
    fun setUp() {
    Dispatchers.setMain(StandardTestDispatcher())
    }
    @After
    fun tearDown() {
    Dispatchers.resetMain()
    }
    

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28. Flowのテスト
    

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29. class Sample {
    val flow = MutableSharedFlow()
    suspend fun emit(value: Int) {
    flow.emit(value)
    }
    }
    

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30. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    val sample = Sample()
    val result = mutableListOf()
    val job = launch {
    sample.flow.toCollection(result)
    }
    assert(result.size == 0)
    sample.emit(1)
    assert(result.size == 1)
    assert(result.first() == 1)
    job.cancel()
    }
    

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31. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    val sample = Sample()
    val result = mutableListOf()
    // ...
    }
    

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32. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    val sample = Sample()
    val result = mutableListOf()
    val job = launch {
    sample.flow.toCollection(result)
    }
    // ...
    }
    

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33. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    val sample = Sample()
    val result = mutableListOf()
    val job = launch {
    sample.flow.toCollection(result)
    }
    // ...
    }
    

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34. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    // ...
    val job = launch {
    sample.flow.toCollection(result)
    }
    assert(result.size == 0)
    // ...
    }
    

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35. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    // ...
    val job = launch {
    sample.flow.toCollection(result)
    }
    sample.emit(1)
    // ...
    }
    

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36. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    // ...
    sample.emit(1)
    assert(result.size == 1)
    assert(result.first() == 1)
    job.cancel()
    }
    

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37. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    // ...
    val job = launch {
    sample.flow.toCollection(result)
    }
    // ...
    job.cancel()
    }
    

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38. @Test
    fun test() = runTest(UnconfinedTestDispatcher()) {
    // ...
    backgroundScope.launch {
    sample.flow.toCollection(result)
    }
    // ...
    // job.cancel()
    }
    

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39. Turbine
    （時間の都合上省略...）
    https://github.com/cashapp/turbine
    

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40. まとめ
    

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41. ● runTest
    ● StandardTestDispatcher / UnconfinedTestDispatcher
    ● Dispatchers.setMain
    ● backgroundScope
    まとめ
    

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42. ありがとうございました
    

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